What could this be?

Hatchling

my mothers boyfriend found this strange thing that looked like a tooth in his yard, and asked me if I could try and found out what it was on the internet. I took some pictures, but my camera is not that good with macro shots, so they came out a bit undetailed, but I hope you can help me anyway.
The dimensions are ca. 5x2x2 cm. and it was found in Kristiansand, on the southern tip of Norway.

If you have a google image search on 'horse tooth' or 'horse teeth' you will find a few images that really look quite similar. However, I'll shoot off an e-mail to TONMO member GeoffC and see what he thinks. Geoff studies animal bone material as part of his job, he'll have a much better idea than me.

Cuttlefish

Sorry not to see this sooner, I'm not near a computer much at the moment. Anyway, yes I think Phil's right, it looks like a horse tooth from the upper jaw (which are more square in cross section), without actually seeing the tooth it's a bit difficult to say. The root end is shown on your 'right' picture.